采集了全国不同类型的土壤40个,分析了土壤全氮、有机质、固定态铵、剩余有机质(KOBr处理后的土壤有机质)、残渣有机质(KOBr—HF处理后的土壤有机质)含量。结果表明,以2∶1型粘粒矿物为主土壤的残渣有机质含量与固定态铵含量之间呈极显...采集了全国不同类型的土壤40个,分析了土壤全氮、有机质、固定态铵、剩余有机质(KOBr处理后的土壤有机质)、残渣有机质(KOBr—HF处理后的土壤有机质)含量。结果表明,以2∶1型粘粒矿物为主土壤的残渣有机质含量与固定态铵含量之间呈极显著正相关(r=0.831**),晶格之间存在的有机质(即残渣有机质与剩余有机质之差值)含量则与固定态铵含量之间也呈极显著正相关(r=0.832**),而以1∶1型粘粒矿物为主土壤的残渣有机质含量和晶格有机质含量与固定态铵含量不相关;土壤剩余有机质、残渣有机质的含量分别为2.59 g kg-1、3.70 g kg-1,分别占土壤有机质的10%和16%。土壤残渣C/N比(平均值为16.69)明显高于原土壤(平均值为5.37)。展开更多
Incubation experiments were conducted to investigate the dynamics of low- molecufar-weight aliphatic acids in two andosols with and without plant materials. Results showed that amount of low- molecular-weight aliphati...Incubation experiments were conducted to investigate the dynamics of low- molecufar-weight aliphatic acids in two andosols with and without plant materials. Results showed that amount of low- molecular-weight aliphatic acids in soils alone varied considerably with water regime under which the soil was incubated,duration of incubation and soil organic matter content, ranging from 257-860 pmol kg-1 soil I of which 19%~33% was in free state. Incorporation of plant materials increased greatly both the amount and number of members of low- molecular- weight aliphaticacidst and also the proporticn of low-molec "far-weight aliphatic acids occurred in free state. Generally, among these aliphatic acids detected, acetic, propionic, glyoxalic and formic acids were predominant.展开更多
文摘采集了全国不同类型的土壤40个,分析了土壤全氮、有机质、固定态铵、剩余有机质(KOBr处理后的土壤有机质)、残渣有机质(KOBr—HF处理后的土壤有机质)含量。结果表明,以2∶1型粘粒矿物为主土壤的残渣有机质含量与固定态铵含量之间呈极显著正相关(r=0.831**),晶格之间存在的有机质(即残渣有机质与剩余有机质之差值)含量则与固定态铵含量之间也呈极显著正相关(r=0.832**),而以1∶1型粘粒矿物为主土壤的残渣有机质含量和晶格有机质含量与固定态铵含量不相关;土壤剩余有机质、残渣有机质的含量分别为2.59 g kg-1、3.70 g kg-1,分别占土壤有机质的10%和16%。土壤残渣C/N比(平均值为16.69)明显高于原土壤(平均值为5.37)。
文摘Incubation experiments were conducted to investigate the dynamics of low- molecufar-weight aliphatic acids in two andosols with and without plant materials. Results showed that amount of low- molecular-weight aliphatic acids in soils alone varied considerably with water regime under which the soil was incubated,duration of incubation and soil organic matter content, ranging from 257-860 pmol kg-1 soil I of which 19%~33% was in free state. Incorporation of plant materials increased greatly both the amount and number of members of low- molecular- weight aliphaticacidst and also the proporticn of low-molec "far-weight aliphatic acids occurred in free state. Generally, among these aliphatic acids detected, acetic, propionic, glyoxalic and formic acids were predominant.